Ignition coil



March 31, 1931. J. 'r. FlTzsaMMoNs ETAL 1,799,011

IGNITION COIL Filed 0C`t. 4, 1928 g1 JZQHN THTZsSiMMo/vs AND HERMAN Lhqfrzfu..

eff I WM Patented Mar. 31, 1931 UNITED STATES PATENT OFFICE JOHN T. FITZSIMMONS AND HERMAN L. HARTZELL, OF ANDERSON, I1\1'1IiIA'.l\T.A,Y ASSIGN- ORS TO DELCO-REMY CORPORATION, F DAYTON, OHIO, A CORPORATION OF DELA- WARE IGNITION COIL Application led October 4, 1928. Serial No. 310,292.

ignition coils through the novel construction of the end member of the coil case which supports the terminals of the coil windings, and also to improve the support of the winding assembly, whereby insulation of the coil terminals is assured, and in which the coil assembly is properly insulated and supported with relation to the enclosing case.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings, wherein a preferred embodiment of one form of the present invention is clearly shown.

In the drawings Fig. 1 is a plan view of the coil.

Fig. 2 is a longitudinal sectional view thereof. y

Figs. 3 and 4 are plan and cross sectional views of a metal insert around which the material, forming the terminal supporting cover of the coil case, is molded.

Fig. 5 is an insulating block which supports the center core and windings ofthe 0 coil.

Fig. 6 is a fragmentary'view of the material which is used to provide the kexternal magnetic circuit of the coil. A

Fig. 7 is a sectional view on 4the line 7*-7 of flange 27 of the case tube 20 as indicated at 28 in Fig. 2. The body provides a .cable receiving sleeve 29 havmg a metal lining member 30 adapted to receive a terminal clip attached to a wire for connecting the sleeve i with the ignition distributor. The body 23 vis also molded around the grooved heads 31 of terminal screws 32 which cooperate with washers 33, terminal clips 33a and nuts 34 to secure to the terminals the conductors which connect the coil with a current source and the ignition timer. Within the oase 20 the body 23 is provided with an annular iiange or skirt 35 which provides a central recess 36 for receiving one end of the central core of the coil which comprises a bundle of iron wires 37.

A secondary -winding 39 is wound around a non-conducting tube 38 and a primary' winding 40 is wound around the secondary 39. The core wires 37 are next inserted within the tube 38. A non-conducting block 41 having a central recess 42 is placed upon a suitable horizontal support and the upper surface 43 and the wall 44 defining the recess 42 are coated with aplastic insulating material such as a mixture of beeswax and rosin maintained at a tem erature suiiciently high to permit sprea ing it with a brush. In practice the non-conducting block 41 is of rectangular formation and of a size that will be nicely received within the case and position the the inner end of the coil windings assembly, the diagonals of the block across the top surface as viewed in Fig. 5 being substantially equal to the diameter of the space Within the case as it is lined with the external magnetic circuit material later described. By this structure the central support of the winding assembl within the case is assured, and provision 1s made for the reception of suitable sealing compound such as hydraline for the positive retention of the block and coil assembly in proper place.

The assembly of core wires and coil windings is placed upon the block 41 before placing these parts within the coil case. The inside lead 45 of the secondary coil 39 is placed against the core wires 37 and is held there by a short non-conducting tube 46. The outside lead 47 of the secondary 39 and the inside lead 48 of the primary 40 are twisted together and are enclosed by a fabric sleeve 49. The outside lead 50 of the primary 40 is inserted through a fabric sleeve 51. A non-conducting tube 52 is placed aroundthe spirally wound margins of paper 53 which 'are used to insulate the layers of secondary windings and which project beyond the ends of the layers. The lower spirally wound paper margins 54 rest directly upon the surface 43 of the block 41.

The external magnetic circuit of the coil is provided by a plurality of turns of magnetizable sheet iron 55 which is wound with a strip of insulating paper 56 into cylindrical form, the paper insulating the turns of sheet iron from each other, the outside edge of the magnetizable stri 55 being permitted to touch the metal tu e 20, in order to provide a ground for the external magnetic circuit. To reduce eddy current losses, the iron sheet 55 is sheared from one side margin nearly across to the opposite side of the margin so as to provide a plurality of strips 57 which extend lon itudinally of the coil and which are joined y the spirally wound margin 58.l

In assembling, the rolled up iron strip 55 is first placed within the coil case, and then I 'a quantity of melted insulating compound is poured in which partly fills the case, and

` following this the assembly of windings, core and insulating block 41 are inserted within the coil case and magnetic winding and forced into the melted material as shown in Fig. 2. Before the non-conducting cover 23 is attached to the case tube 20, the coil leads 47 and 48 are threaded through a hole 60 in one of the terminal studs 32, and the lead 50 representedlin Fig. 2 by the portions crosssectloned with heavy alternately vfull and broken ylinesvas at 70.

`It will be noted that this insulating com pound fills all the voids between the windings,

the external magnetic iron and the` coil case.

Before the insulating compound-has had time to cool,the non-conducting cover 23 is placed upon the case tube 20. The insert ring 24 is united with ythe fiange 27 of the tube 2O in the mannerv shown, and thevseam 28 j may be soldered if desired. The ends of the leads 47, 48 and 50 which extend through the holes 60 and 61 are soldered tothe heads 3] of studs 32. The end face groove 31a in each stud head 3].w receives the end portion of a v fm head ofthe nail engages the bottom of the sleeveBO. v"The shank of the nail will extend into the bundle. of wires 37. A lead plug 66 is forced into the sleeve 30 in order to provide aseal which will prevent moisture from entering the coil around the nail 65.

When the cover 23 is placed on the 'tube 20, the skirt 35 will enter the body of-molten insulating compound 70, and will displace some ofit and will cause it to iow into spaces above the upper end of the core 37 and the tube 52. In this manner the inside secondary lead 45 is effectively insulated from the outside lead 47. While the form of embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms' might be adapted, all coming .within the scope of the claims which follow.

What is claimed is as follows In an ignition coil, having a coil assembly and an enclosing case, a cover therefor, comprising al body of insulating material molded to embrace a flanged retaining ring, said body being provided with a centrally disposed terminal receiving cup on one side, and concentric annular skirts on the other side, one of the skirts telescopically engaging a member of the coil assembly to position it within the case, said skirts also serving to spread a filler of insulating compound, and force it into the voids between the elements of the coil assembly and insulate the leads of the coils.

In testimony whereof we hereto affix our JHN T. FITZSIMMONS. HERMAN L. HARTZELL.

signatures. 

